Maritime record MDO20123 - Portland Stone Boat

The overall appearance of the wreck site as well as the absence of discarded fishing lines, hooks and weights, suggests that it has not previously been visited by divers, fishermen or anglers even though it is located in an area popular with diving clubs and charter boats serving the local diving and angling industry. The use of trawls and scallop-rakes by commercial fisherman and the practice of anchoring large naval and merchant vessels in the area also luckily appear to have missed this site.

A visual pre-disturbance survey, video/DVD recording and still photographs were initially taken followed by geo-physical surveys using sidescan sonar and multi-beam swath bathymetric sonar which gives a 3D image of the site above the seabed: the later was carried out by the Nautical Archaeology Society.
The overall size of the site is approximately 25 metres by 15 metres and rises approximately 2 metres from the seabed. The vessel is of wooden construction with a cargo of approximately 65 to 75 tons of cut Portland stone and, based on the location of the anchor, it is assumed to have been heading North by Northwest at the time of the sinking.

Due to the height of the cargo exposed above the sea bed a framework of four datum lines were laid around the wreck site, aligned to woodwork exposed at the stern, to enable a survey to be made. The cargo consists of at least 46 cut, but not finished, Portland stone blocks that have been numbered and measured, which vary in size from the biggest at 1.83m.x0.91m.x0.84m. (6’x3’x2’9”) weighing an estimated 3.36 tonnes down to a block weighing just 67kg and measuring 0.53m.x0.23m.x0.23m. (1’9”x9”x9”). From the geo-physical surveys there appears to be a debris trail to the south consisting of 5 further blocks that were probably shed as the vessel sank.

Objects that were lying on the surface of the sea bed and at risk from fishing trawls were recorded and planned in situ before being raised, photographed and put into appropriate conservation, drawing on the experience gained from the Earl of Abergavenny project. Objects recovered include a deadeye frame, pulley-block and hemp rope that were part of the vessel, along with items used on board including a copper alloy halfpenny of 1721, parts of a cooking pot, pewter spoon, axe, “steelyard” weights and shot from a 24 bore carbine, presumably on board to protect the boat from French privateers. Hand made bricks and Old Devonian red sandstone slabs or pavers have also been found. The appropriate documentation for the Receiver of Wreck has been submitted.
After measurement, survey and photography a pair of cut Portland stone arches from the cargo, that had fallen forward during the sinking, over what appears to be the cooking area, were raised. It was hoped that closer examination could assist with the identification of the source of the cargo from masons marks and geologist analysis and hence to the identification of the vessel. This also had the benefit that it will allow a particularly interesting area of the vessel to be surveyed in detail. The stone arches are currently on display outside Weymouth Museum.

Based on artifacts recovered, initial indications suggest the date of the sinking to be mid eighteenth century. To date no construction records or pictures of sailing vessels used to transport Portland stone in the eighteenth century have been found.

Position 50 34.865 N 2 22.112 W supplied by the finder, Ron Howse.

Horizontal Datum: OGB (1)(2)
Vertical Datum: LAT (1)(2)
Quality of Depth: echosounder (1)(2)
General Depth: 24 metres (1)(2)
Orientation: 050/230 (1)(2)

Position 50 34.575N 002 22.840W (OSGB); 50 34.610N 002 22.919W (WGS 84).

13-OCT-1990: Obstruction, 20 x 0.5 metres, orientated 050/230 degrees examined in 50 34.34.5N 002 22.50.4W. Least echosounder depth 23.7m in general depth 24.4m. No scour. Height 2.1m. Man-made and pipe-like. (1)(2)

Seen to be located approximately 1.25 miles east of Outer Breakwater, Portland; no other recorded wrecks in vicinity. (3)

Multibeam image of stone cargo covering the wreck. (5)

<1> United Kingdom Hydrographic Office, 1992, Hydrographic Office wreck index (Index). SWX4837.

<2> United Kingdom Hydrographic Office, Wreck report, 18778 (Monograph). SDO20514.

<3> SeaZone Hydrospatial, Digital marine geographic information derived from SeaZone Hydrospatial, 30-JUN-2011 (Digital archive). SDO20540.

<5> http://www.weymouthlunarsociety.org.uk/, stonewrecks.htm > accessed on 30-JUN-2011 (Digital archive). SDO20665.

<6> National Record of the Historic Environment, 832514 (Digital archive). SDO14739.

Record last edited

May 2 2024 12:39PM